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