How can I display generators or a minimal generating set with GAP? The following commands
gap> G:=SmallGroup(6,1);
<pc group of size 6 with 2 generators>
gap> GeneratorsOfGroup(G);
[ f1, f2 ]
gap>

display the generators of $G$ in a rather abstract way. The command StructureDescription helps to understand the structure of the group, but does not tell anything about generators or generating sets. In particular, how do I get the size of a minimal generating set of some group ?

How can I display the generators or a minimal generating set more concrete, for example a^2=b^3=ab^2=e or something like that ? $f_1$ and $f_2$ is not helpful to understand the structure of a group. 

UPDATE : I just found an answer that could help me. The following commands give
the relations of the group.
gap> H:=Image(IsomorphismFpGroup(G));
<fp group of size 6 on the generators [ F1, F2 ]>
gap> RelatorsOfFpGroup(H);
[ F1^2, F2^-1*F1^-1*F2*F1*F2^-1, F2^3 ]
gap>

Is this a presentation of the given group ?

For a pc group (polycyclic presentation), RelatorsOfFpGroup(Range(IsomorphismFpGroup(G))) will return defining relators in these generators which can be interpreted as either expressing generator powers or generator commutators in terms of "lower order" generators. This can represents some semidirect product structure.
Otherwise one would have to find "nice" generators by hand, the question
Presentation for hand calculation
might give a bit of an idea how to do so.
You can compute a minimal (with respect to cardinality) generating set as
gap> MinimalGeneratingSet(G);
[ f1, f2 ]

(this will work only for solvable groups. In general there is SmallGeneratingSet that does not guarantee minimal cardinality), but in this case it will give you the same generators as before.
MinimalGeneratingSet will only give a generating set of minimal cardinality -- it is not a generating set with respect to which a presentation would be particularly nice.
