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