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