For security reasons this is not recommended but if you're the only one with access to your instance you can disable the password by editing the sudoers file, there's even a command for that:
That will open the file for edit in your favorite text editor in where you should look for this line:
%sudo ALL=(ALL:ALL) ALL
Replace it with:
%sudo ALL=(ALL:ALL) NOPASSWD:ALL
Then save the file and you should never be prompted for sudo password again.