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