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