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