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