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