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