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