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