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)(11,17,20,24)(12,21,18,15)(14,22,23,19)(25,26,30,34)(27,35,37,39)(28,33,29,32)(31,36,40,38)(1,3,4,8)(2,5,6,7)(27,36)(28,29)(31,39)(32,33)(35,40)(37,38)(9,11,18,22,13,20,12,19)(10,14,21,24,16,23,15,17)(25,27,29,36,30,37,28,38)(26,31,33,39,34,40,32,35)(2,6)(5,7)(27,37)(31,40)(35,39)(36,38) 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.