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