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