GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
#g3 f1 6x6 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 -1 0 0 1 0 0 0 -1 0 0 1 0 0 0 -1 0 0 1 6x6 0 0 0 1 0 -1 0 0 0 0 0 -1 0 0 0 0 1 -1 1 0 -1 0 0 0 0 0 -1 0 0 0 0 1 -1 0 0 0 6x6 0 1 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 1 6x6 6 -2 -2 -3 1 1 -2 6 -2 1 -3 1 -2 -2 6 1 1 -3 -3 1 1 6 -2 -2 1 -3 1 -2 6 -2 1 1 -3 -2 -2 6 2^5 * 3^2 = 288