You can enter these cheats in to the command console brought up with the ~ (tilde) key, most seem to have the same effect as in Fallout 3, just now with different item codes to activate them. The list of codes can be seen below
(Adding more codes as they become available)
Saints Row IV Commander In Chief Edition Cheat Code
Pause the game, and select the "Extras" option, then choose the "Cheats" selection. Select "Add Cheat" and enter one of the following codes to activate the corresponding cheat function. If you entered the code correctly, you will hear a sound. Note: Achievements and auto save are disabled when cheats are activated. However, you are still allowed to manually save while cheats are enabled.