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