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