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