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