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