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)(11,17)(12,20)(13,15)(14,18)(16,21)(19,22)(23,24)(25,26,31,33,30,27,29,34)(28,35,36,39,38,32,37,40)(2,5)(6,7)(9,11)(10,14)(12,19)(13,18)(15,17)(16,22)(20,23)(21,24)(25,27,30,26)(28,32,38,35)(29,34,31,33)(36,39,37,40)(1,3,4,8)(2,6,5,7)(10,15)(11,18)(16,20)(19,24)(25,28)(26,32)(27,35)(29,37)(30,38)(31,36)(33,40)(34,39)(11,18)(14,17)(19,24)(22,23)(26,27)(32,35)(33,34)(39,40) involution — undirected(9,12,13,21)(10,16,15,20)(11,19,18,24)(14,22,17,23)(25,29,30,31)(26,33,27,34)(28,36,38,37)(32,39,35,40)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.