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