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