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