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