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