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