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