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