PermRep(G, K)
PermRep
calculates the permutation representation of the finitely
presented group F on the right cosets of the subgroup K, and returns
it as a permutation group of which the generators correspond to those
of F. It simply calls the GAP Todd-Coxeter function. Of course,
there is no guarantee in general that this representation will be
faithful.
GAP 3.4.4