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