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)(27,31)(28,33)(29,32)(30,34)(35,39)(36,38)(37,40)(1,2)(3,7)(4,6)(5,8)(9,11,13,18)(10,14,16,17)(12,19,21,24)(15,22,20,23)(25,27)(26,31)(28,37)(29,36)(30,35)(32,38)(33,40)(34,39)(1,3)(2,5)(4,8)(6,7)(26,32)(28,29)(31,38)(33,34)(36,37)(39,40) involution — undirected(2,6)(3,8)(11,18)(14,17)(19,24)(22,23)(27,35)(31,39)(36,37)(38,40) involution — undirected(2,6)(5,7)(9,12,13,21)(10,15,16,20)(11,19,18,24)(14,22,17,23)(25,28,30,29)(26,33,34,32)(27,36,35,37)(31,38,39,40)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.