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