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