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