One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,6)(5,8)(9,10)(11,17)(12,20)(13,16)(14,19)(15,22)(18,23)(21,24)(25,26,31,36)(27,37,28,33)(29,35,30,34)(32,39,40,38)(1,3,4,8)(2,5,6,7)(9,11,13,19)(10,14,16,17)(12,21,22,18)(15,24,20,23)(27,28)(32,40)(33,37)(38,39)(3,8)(5,7)(25,27,31,28)(26,32,36,40)(29,38,30,39)(33,34,37,35)(2,6)(5,7)(9,12,13,22)(10,15,16,20)(11,18,19,21)(14,23,17,24)(25,28,31,27)(26,33,36,37)(29,38,30,39)(32,34,40,35)(10,16)(14,17)(15,20)(23,24)(25,29,31,30)(26,34,36,35)(27,38,28,39)(32,37,40,33)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.