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