Access Windows Virtual Machine Localhost from Host Mac
There is a major difference in using IIS Express and the 'regular' IIS. The latter as installed by default in Windows.

In short, IIS Express runs sandboxed on its host environment. This means by default it cannot be accessed outside. Luckily, you're not the only one asking this as it has been adressed on StackOverflow several times. In my opinion, with this post having one of the better answers.

For future reference, this means:


Edit the applicationhost.config file (which holds info and bindings to all your IIS Express projects ever ran locally)
Execute the netsh http add urlacl url=http://*:8080/ command (possibly some other)
Open up the Windows Firewall to allow IIS Express and the desired ports to be accessed 'externally' (yes, your Mac = external, as far as Windows is concerned)


As a final tip I'd like to suggest to also add your Windows' system name to the Mac host file. This can easily be done running the following command in the OSX Terminal: 


  sudo nano /etc/hosts


By adding the Windows system name you can now use it to navigate to http://your-win-name instead of having to point to an IP Address.

Good luck!