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