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