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