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