Did Voldemort look the same as he does in books 6 and 7 after killing Lily and James? I would think he would look more human, but maybe the dark magic changed his appearance after he left Hogwarts.
When Voldemort regains his body he looks like this
Voldemort looked away from Harry, and began examining his own body. His hands were like large, pale spiders; his long white fingers caressed his own chest, his arms, his face; the red eyes, whose pupils were slits, like a cat’s, gleamed still more brightly through the darkness. He held up his hands, and flexed the fingers, his expression rapt and exultant.
This is all due to the transfiguration he did on his body Before going to the Potters.
Years prior to the attack,
His features were not those Harry had seen emerge from the great stone cauldron almost two years before; they were not as snakelike, the eyes were not yet scarlet, the face not yet masklike, and yet he was no longer handsome Tom Riddle. It was as though his features had been burned and blurred; they were waxy and oddly distorted, and the whites of the eyes now had a permanently bloody look, though the pupils were not yet the slits that Harry knew they would become. He was wearing a long black cloak and his face was as pale as the snow glistening on his shoulders.
Voldemort already looked "almost" like in the years preceding the start of the first Wizarding war in which the potters died. This shows he has been actively modifying his appearance for years. Additionally When did Tom Riddle get his new face?
He looked like he did when ‘reborn’.
The Dark Lord looked the same when he killed the Potters as he did when he was restored to a body. When Harry sees him, Harry sees ‘the face that had haunted his nightmares for three years’.
“The thin man stepped out of the cauldron, staring at Harry … and Harry stared back into the face that had haunted his nightmares for three years.”
- Harry Potter and the Goblet of Fire, Chapter 32 (Flesh, Blood and Bone)
The nightmares Harry refers to are likely the ones he has of the night his parents died, meaning the Dark Lord looked the same then.
He had a gradual transition from the handsome T.M. Riddle to Voldemort, looking less human and more snakelike with each Horcrux he created. If you're talking about the time just before accidentally making Harry into a Horcrux (when he perished at the Potter's house), he would have looked the same as he did when Harry saw him resurrected. People at the MoM who saw Voldemort in the battle at the end of OotP used their seeing him as what jolted them to the realization that Voldemort was indeed back, which would not have happened if he looked different before Halloween, 1981.