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