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