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