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