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