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