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