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