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