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