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)(27,37)(28,34)(29,30)(31,35)(32,36)(33,40)(38,39) involution — undirected(1,2)(3,6)(4,5)(7,8)(10,15)(12,22)(16,18)(19,23)(25,27)(26,33)(28,38)(29,35)(30,39)(31,34)(32,40)(36,37) involution — undirected(2,5)(6,8)(10,15)(13,17)(16,18)(20,24)(25,28,32,29)(26,34,36,30)(27,38,40,35)(31,37,39,33)(3,7)(6,8)(9,11,14,21)(10,16,15,18)(12,23,22,19)(13,20,17,24)(25,29,32,28)(26,34,36,30)(27,35,40,38)(31,37,39,33)(1,3,4,7)(2,6,5,8)(9,12)(10,17)(11,19)(13,15)(14,22)(16,20)(18,24)(21,23)(25,30,32,34)(26,29,36,28)(27,39,40,31)(33,35,37,38)(1,2)(3,6)(4,5)(7,8)(9,13,14,17)(10,12,15,22)(11,20,21,24)(16,23,18,19)(25,31,32,39)(26,35,36,38)(27,34,40,30)(28,33,29,37)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.