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