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