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