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