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