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