Hi game123 ,
You can achieve that by using Trusted Network detection along with Always on with fail-open policy in case the VPN fails to connect .
Below are some documents for your reference
https://supportforums.cisco.com/document/59201/anyconnect-trusted-network-detection-tnd-and-always-troubleshooting-faqs
http://www.cisco.com/c/en/us/td/docs/security/vpn_client/anyconnect/anyconnect31/administration/guide/anyconnectadmin31/ac03vpn.pdf
Regards
Shakti