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