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