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