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