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