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