You can also specify groups in the /etc/sudoers file. The group name is preceded by the percentage character as follows:
%group hosts=(user:group) commands
The following rule will grant the developers group permission to install any package on the system:
%developers ALL=(ALL) NOPASSWD: /usr/bin/apt-get install
The following rule will grant the developers group permission to run any command on the system:
%developers ALL=(ALL) NOPASSWD: ALL