Need help with creating a laboratory map

So, I'm running a one-shot in a biopunk setting and I'm planning on running the players through a laboratory dungeon. The problem is that I've never made a dungeon before and I'm bad at making maps in general.

Basically, it's a 3-floor dungeon. The first is fairly normal, with the walls and machinery being made of stones and plants with some metal here and there (since metal is pretty rare in this setting), the second is where the machines and other technical stuff start to be made out of flesh and other human parts while still remaining mostly normal, and the third is the big jump where everything, even parts of the walls, is made from human. I'm most likely going to have the third floor be a bit lopsided at parts.

Any help or guides are welcome