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