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