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