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