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