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