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