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