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