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