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