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