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