The answer is on page 24 of your user manual.
It says: "If the printer requires 110-127 volts of power, You must unplug the printer to turn the power off. If the printer requires 220-240 volts, you can switch the printer off (the switch is located on the left side of the power plug) or unplug it."
You can also plug the power brick into a switched power center box and turn it off there.