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