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