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