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