One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,5)(4,6)(7,8)(9,10)(11,17)(12,16)(13,15)(14,19)(18,24)(20,22)(21,23)(25,26,30,34)(27,35,38,49)(28,32,40,46)(29,42,36,33)(31,43,45,39)(37,48,51,56)(41,53,50,47)(44,54,55,52)(1,3)(2,5)(4,7)(6,8)(9,11,13,19)(10,14,15,17)(12,20,21,18)(16,24,23,22)(28,40)(32,46)(37,51)(41,50)(44,55)(47,53)(48,56)(52,54)(2,6)(3,7)(25,27,36,43,30,38,29,39)(26,31,42,49,34,45,33,35)(28,37,50,54,40,51,41,52)(32,44,53,56,46,55,47,48)(10,15)(14,17)(16,23)(22,24)(25,28)(26,32)(27,37)(29,41)(30,40)(31,44)(33,47)(34,46)(35,48)(36,50)(38,51)(39,52)(42,53)(43,54)(45,55)(49,56) involution — undirected(3,7)(5,8)(9,12,13,21)(10,16,15,23)(11,18,19,20)(14,22,17,24)(27,38)(28,40)(31,45)(32,46)(35,49)(39,43)(41,50)(47,53)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.