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