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