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