I'm installing an expansion cabinet on a STSE system. I received
the cabinet but not the amphenol cable to connect the cabinets.
I have a butterfly tool and could make my own unless the wiring
is not standard. Does anyone know? Thanks.

It is not the standard 25 pair connection...and there is not much chance you will find a wiring diagram. The proper cable is something that a reseller should be able to provide.