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