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