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