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