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