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