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