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