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