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