I was wondering about this too when I first got the car! Unfortunately, the MK2 doesn't have a built-in digital speedometer option in the multi-info display. The screen is pretty basic and mostly just handles the trip meter, fuel range, and MPG.
If you really want a digital readout, your best bet is probably plugging a cheap OBD2 heads-up display (HUD) into the port under the dash, or just using a GPS speedo app on your phone. A bit annoying that it's not built-in, but you get used to the analog dial pretty quickly!