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