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