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