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