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