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