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