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