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