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