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