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