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