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