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