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