gap> mat := [[0,2,0,0],[2,0,0,0],[0,0,0,5],[0,0,5,0]]*Z(7)^0;
[ [ 0*Z(7), Z(7)^2, 0*Z(7), 0*Z(7) ], [ Z(7)^2, 0*Z(7), 0*Z(7), 0*Z(7) ],
[ 0*Z(7), 0*Z(7), 0*Z(7), Z(7)^5 ], [ 0*Z(7), 0*Z(7), Z(7)^5, 0*Z(7) ] ]
gap> phi := HermitianPolarityOfProjectiveSpace(mat,GF(49));
<polarity of PG(3, GF(7^2)), >
gap> CompanionAutomorphism(phi);
FrobeniusAutomorphism( GF(7^2) )