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