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