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