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