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