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