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