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