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