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