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