Na xkbprint
man page , mostra ..
-label type Specifies the labels to be printed on keys; legal types are: none, name,code,symbols.
Suponho, portanto, que isso deve ser útil para você:
xkbcomp /usr/share/X11/xkb/geometry/microsoft - | xkbprint -label symbols -color -o - - | ps2pdf - > out.pdf