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