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