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