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