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)(11,20)(12,25)(13,29)(14,19)(15,23)(16,27)(17,24)(18,31)(21,35)(22,33)(26,38)(28,37)(30,36)(32,39)(34,40) involution — undirected(1,3,5,4)(2,6,7,8)(9,11)(10,15)(12,26)(13,22)(14,23)(16,34)(17,29)(18,33)(19,20)(21,27)(24,31)(25,32)(28,39)(30,40)(35,36)(37,38)(1,4,5,3)(2,6,7,8)(9,12,14,28)(10,16,19,36)(11,21,23,40)(13,30,31,27)(15,32,20,38)(17,35,33,34)(18,37,29,25)(22,26,24,39)(9,11)(10,17)(12,21)(13,22)(14,23)(15,18)(16,35)(19,33)(20,29)(24,31)(25,38)(26,30)(27,39)(28,40)(32,37)(34,36) involution — undirected(2,7)(6,8)(9,13,14,31)(10,18,19,29)(11,22,23,24)(12,27,28,30)(15,33,20,17)(16,25,36,37)(21,39,40,26)(32,35,38,34)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.