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