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