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