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