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