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