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