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