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