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