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