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