Automorphisms of graph with intersection array $\{64,42,1;1,21,64\}$

Prime divisors of orders of automorphisms and the fixed point subgraphs of automorphisms of prime orders are studied for a hypothetical distance-regular graph with intersection array $\{63,60,1; 1,4, 63\}$. Let $G={\rm Aut}(\Gamma)$, $\bar G=G/S(G)$, $\bar T$ is the socle of $\bar G$. If $\Gamma$ is vertex-symmetric then the possible structure of $G$ is determined. In the case $\bar T\cong U_3(3)$ graph exist and is arc-transitive.