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