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