One way is to duplicate your aliases for the root user, too. By e. g. putting them in `/root/.bashrc`.
Perhaps an easier way is to simply put this in your `.bashrc`:
`alias sudo='sudo '`
The space after `sudo` is important. According to the bash manual:
> If the last character of the alias value is a space or tab character, then the next command word following the alias is also checked for alias expansion.