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