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