Just trace the cables physically, if you can't disconnect them.
have you considered LanSurveyor?
Orion NMP v10 can do this using network sonar. You can review the SW blog entry which explains it better than I can here:
Additionally you could also use the switch port mapper from the Engineering Toolset (A totally different product) to map out switches one at a time.
I’d personally recommend the NPM option since NPM gives you a lot of tools to work with for network monitoring. However the Eng. Toolkit can work as a starter solution if the budget is tight, our company did that for several years before we could get Orion.