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