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