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