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