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