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