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