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