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