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