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