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