Hello,
Unfortunately, there does not seem like a way to enable read-only access for
the GUI on the switch. Both regular web GUI as well as CNA require level_15
access. You could try TACACS based command authorization and see if that
helps.
http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/1
2.1_19_ea1/configuration/guide/swauthen.html#wp1036936
Hope this helps.
Regards,
NT