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