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