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