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