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