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