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