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