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