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