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