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