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