Don't have a CAD drawing for you.
Suggest you just search the internet for some commercial manufacturers of a 4'x8' cnc router.
Not much to draw it from a picture for a footprint of the machine and controls, etc.
Then consider leaving 3 ' wide access all around, allow for full size sheet insertion to the machine, maybe a small bridge crane / suction
handling of the sheets ( floor or hung from the ceiling), also sheet staging and storage, tool cabinet etc.
FWIW,
RICH