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