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