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