[user@localhost ~]$ su -
Password:
Last login: ...
[root@localhost ~]# usermod -aG wheel user
[root@localhost ~]# exit
logout
[user@localhost ~]$ sudo echo 123
[sudo] password for user:
user is not in the sudoers file.  This incident will be reported.

## Allows people in group wheel to run all commands
# %wheel        ALL=(ALL)       ALL

## Same thing without a password
# %wheel        ALL=(ALL)       NOPASSWD: ALL