Terminal - don't require password for shell script to run
You can add a rule to the /etc/sudoers file to give your user access rights to networksetup without a password.


Note the user name of the user account which should be allowed to run the command (you can get the user name by running whoami in Terminal)
Log in as an admin user
Open Terminal
VISUAL=nano sudo visudo - opens the sudoers file in a kind of friendly editor
Jump to the bottom
Add

USERID-FROM-STEP1 ALL = NOPASSWD: /usr/sbin/networksetup


followed by an empty line(!)
Save and quit


You should now be able to run networksetup as the user from step 1 without a password prompt by simply entering sudo networksetup.