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