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