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