When you said "who have access on whom EV page" are you referring to EV web pages from IIS or any option through the Enterprise Vault Admin Console? For IIS, you can easily review the IIS logs from the Enterprise Vault server for compliance purposes. However, for all the Enterprise Vault options (or process) auditing would be an option:
http://www.symantec.com/docs/TECH49054
In the Enterprise Vault server properties > Auditing Tab, there is an option called "User" where you could write a VBS script or ASP page to design your own audit entries, but of course, you need to know a little bit about programming to use that option.
I hope this helps.