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