add your user account to be part of admin and sudo group.
And change the entry as below:
(NOTE: not a best practice for system security in mind, but happy for those lazy-to-type-password like me..)
$ sudo visudo
# Members of the admin group may gain root privileges
%admin ALL=(ALL) NOPASSWD:ALL
# Allow members of group sudo to execute any command
%sudo ALL=(ALL) NOPASSWD:ALL