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