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