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