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