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