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