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