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