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