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