Internet Topology Zoo
A recent article published on slate provided nice artistic views about the layout of the optical fibers that are used for Internet.
Researchers have spent a lot of time to collect data about ISP networks during the slate decade. If you are looking for nice maps about real networks, I encourage you to have a look at the Internet topology zoo. This website, maintained by researchers from the University of Adelaide contains maps of a few hundred networks, an excellent starting point if you would like to understand a bit more on ISP networks are designed.
If you are more interested by the layout of cables, notably submarine cables, you can also check the geographical maps provided by telegeography.