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