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