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