One vertex per element, one color per generator, with an edge from x to x·s.
(9,10)(11,18)(12,16)(13,22)(14,17)(15,21)(19,24)(20,23)(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)(3,7)(4,6)(5,8)(9,11)(10,15)(12,19)(13,20)(14,21)(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)(2,5)(4,8)(6,7)(9,12,14,13)(10,16,17,22)(11,19,21,20)(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)(2,6)(3,8)(9,12,14,13)(10,16,17,22)(11,20,21,19)(15,24,18,23)(25,28)(26,33)(27,38)(29,41)(30,42)(31,45)(32,47)(34,49)(35,50)(36,40)(37,52)(39,53)(43,56)(44,48)(46,55)(51,54)(2,6)(5,7)(9,13,14,12)(10,16,17,22)(11,20,21,19)(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.