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