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