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