Have you looked into NetApp Synergy, specifically Storage Design Studio? It has controller data import tools (including from live system AutoSupports), and automation of documentation tools, including output to Word, Excel, and Visio. Caveat: some of the export tool levels may only be visible to NetApp employees, partners, and/or NCDA certified persons. Link: http://synergy.netapp.com/
It may not be quite as sophisticated a diagramming tool as you might be looking for, but I don't know if Visio supports that sort of "peel back the onion" functionality - at least, our automation scripting doesn't (yet). It still could be done manually, by adding hyperlinks inside the Visio diagrams, though. See also the SDS Community Link: Storage Design Studio