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