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