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