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