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