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