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