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