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