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