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