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