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