Cisco UCS Visio Stencils — Use the link below and scroll down to “Unified Computing and Servers”, and select “Unified Computing System” and download the zip file.

http://www.cisco.com/en/US/products/hw/prod_cat_visios.html

Currently (as of 12/2014) you can cut to the chase and use the direct link below:

http://www.cisco.com/c/dam/assets/prod/visio/visio/Unified_Computing_System.zip