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