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