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