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