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