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