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