Remark: Moore/Coxeter presentation (I think). x and y are R.A.Wilson's standard generators for A7. The presentation is available in MAGMA code here. (This applies to the subgroups below too.)
Some subgroups:
Realisation: x = (1, 2, 3) and y = (3, 4, 5, 6, 7).
The above permutations are available in MAGMA format here.
Remark: Moore/Coxeter presentation. The presentation is available in MAGMA code here. (This applies to the subgroups below too.)
Some subgroups:
Realisation: x = (1, 2, 3, 4, 5, 6, 7) and y = (1, 2).
The above permutations are available in MAGMA format here.