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