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