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