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