In the Print dialog you should see a drop down menu below the orientation icons. Select Printer Features from the drop down menu. If there is a setting or menu to select draft resolution select it. Then in the Presets drop down menu at the top of the dialog select Save As, provide a name to use for the settings, then save them. I believe each time you want to use draft printing you can then select your customized preset from that menu.
The alternative, if possible, is to use the front panel of the printer to set Draft as the printer's default setting. You will need to consult the printer's user manual to see how that can be done.