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