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