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