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