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