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