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