  We show that stimulated Raman adiabatic passage (STIRAP) and its
superadiabatic version (saSTIRAP) have a natural geometric two-star
representation on the Majorana sphere. In the case of STIRAP, we find that the
evolution is confined to a vertical plane. A faster evolution can be achieved
in the saSTIRAP protocol, which employs a counterdiabatic Hamiltonian to
nullify the non-adiabatic excitations. We derive this Hamiltonian in the
Majorana picture, and we observe how, under realistic experimental parameters,
the counterdiabatic term corrects the trajectory of the Majorana stars toward
the dark state. We also introduce a spin-1 average vector and present its
evolution during the two processes, demonstrating that it provides a measure of
nonadiabaticity. We show that the Majorana representation can be used as a
sensitive tool for the detection of process errors due to ac Stark shifts and
non-adiabatic transitions. Finally, we provide an extension of these results to
mixed states and processes with decoherence.
