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