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