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