G is the group 243gp21
G has 2 minimal generators, rank 2 and exponent 27. The centre has rank 2.
The 4 maximal subgroups are: Ab(9,9), Ab(27,3) (3x).
There is one conjugacy class of maximal elementary abelian subgroups. Each maximal elementary abelian has rank 2.
At present no information on the cohomology ring.