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