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