One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(3,7)(9,10,14,17)(11,18,20,15)(12,16,13,22)(19,24,21,23)(25,26,29,31)(27,35,36,51)(28,33,41,45)(30,43,37,34)(32,46,44,39)(38,50,40,54)(42,56,52,49)(47,55,48,53)(1,2)(3,8)(4,5)(6,7)(9,11)(10,15)(12,19)(13,21)(14,20)(16,23)(17,18)(22,24)(26,31)(27,36)(33,45)(34,43)(38,40)(39,46)(49,56)(53,55) involution — undirected(1,3)(2,6)(4,8)(5,7)(9,12,14,13)(10,16,17,22)(11,19,20,21)(15,23,18,24)(25,27,37,46,29,36,30,39)(26,32,43,51,31,44,34,35)(28,40,52,53,41,38,42,55)(33,48,56,50,45,47,49,54)(3,7)(6,8)(11,20)(15,18)(19,21)(23,24)(25,28,29,41)(26,33,31,45)(27,38,36,40)(30,42,37,52)(32,47,44,48)(34,49,43,56)(35,50,51,54)(39,53,46,55)(1,4,5,2)(3,8,7,6)(9,13,14,12)(10,16,17,22)(11,21,20,19)(15,23,18,24)(26,31)(27,36)(28,41)(34,43)(39,46)(42,52)(47,48)(50,54)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.