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