One great product I like to use is Nessus.
Nessus has plugins available to both import existing nmap scan results and launch nmap scans directly. I like the reporting features of the tool which will output a nice PDF report for you.
See this link for more information.
Another alternative I like to use is the Metasploit framework. While renowned as an exploit framework, my favorite function of Metasploit is actually it's database. I use it to gather the results of my various scans and other activities during a penetration test. You can import nmap and other scans into the framework and view the information in it there. It doesn't have a pretty interface, but it's functional and works well.
Both the tools I mentioned might be a little heavy to use just as a nmap scan viewer. For something a little more lightweight, just share the results in the human readable output in something like Dropbox, not as pretty but just as functional.
You mention features like automatically drawing network maps based on scans. The zenmap GUI utility, usually packaged with the official nmap distribution actually has that feature. I have not used it extensively but you might want to give it a shot.
For comparison of two different scans of the same host, try ndiff, which again comes packaged with the official nmap install.