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