I am searching internet for good Cisco Visio stencils as previous one are really out dated. These Visio stencils can be used for not only for Cisco but for simple networking diagrams in Visio.
http://www.petenetlive.com/KB/Article/0001041
http://www.cisco.com/c/en/us/products/visio-stencil-listing.html
http://www.petenetlive.com/KB/Article/0001041
http://www.cisco.com/c/en/us/products/visio-stencil-listing.html