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