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