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