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)(11,17)(12,20)(13,15)(14,19)(16,22)(18,23)(21,24)(25,26,32,31)(27,35,30,33)(28,38,34,29)(36,37,39,40)(1,2,4,6)(3,5,8,7)(9,11,13,19)(10,14,15,17)(12,21,22,18)(16,24,20,23)(25,27,32,30)(26,33,31,35)(28,39,34,36)(29,40,38,37)(1,2)(3,5)(4,6)(7,8)(10,15)(14,17)(16,20)(23,24)(25,28)(26,29)(27,36)(30,39)(31,38)(32,34)(33,37)(35,40) involution — undirected(1,3)(2,5)(4,8)(6,7)(9,12,13,22)(10,16,15,20)(11,18,19,21)(14,23,17,24)(25,29,32,38)(26,34,31,28)(27,37,30,40)(33,39,35,36)(9,11)(10,14)(12,18)(13,19)(15,17)(16,23)(20,24)(21,22)(25,30,32,27)(26,35,31,33)(28,39,34,36)(29,40,38,37)(9,10)(11,14)(12,16)(13,15)(17,19)(18,23)(20,22)(21,24)(25,31,32,26)(27,35,30,33)(28,38,34,29)(36,40,39,37)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.