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