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