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