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