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