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