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