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