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