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