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