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