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