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