Symplectic graphs over finite commutative rings

Let VV be a symplectic space over a finite commutative ring RR and let GSpR(V) be the symplectic graph over RR. In this work, we show that it is arc transitive and determine the chromatic number. Moreover, if RR is a finite local ring, we obtain its automorphism group, and the chromatic number and the automorphism group of each subconstituent.