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