GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
#g4 f1 z1 c1 6d0 -1 6x 6 0 1 0 0 0 0 -1 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 1 0 0 0 0 0 0 1 0 0 6x 6 0 1 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 6x 6 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 1 0 0 0 0 0 0 1 0 0 0 0 6x 6 2 -1 0 0 0 0 -1 2 0 0 0 0 0 0 2 -1 0 0 0 0 -1 2 0 0 0 0 0 0 2 -1 0 0 0 0 -1 2 6d0 % zentr -1 6d0 % cen -1 2^7 * 3^4 = 10368 %order of the group