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