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