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