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