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