I mouse over the tab and it shows me the file directory.
Also since you are using Resharper you can use this keyboard shortcut and it will highlight the file in solution explorer.
Alt+Shift+L
Since you are using Resharper you can use its navigation instead of Visual Studio's. In this example you are looking for Default.aspx
Ctrl+Shift+N
That shortcut will bring up its file search screen. Type "Def" and pick the one based on which folder you want.