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