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)(25,26,31,30)(27,34,32,28)(29,33,38,39)(35,40,37,36)(2,3)(6,7)(12,19)(16,22)(18,23)(20,24)(25,27)(26,28)(29,37)(30,34)(31,32)(33,40)(35,38)(36,39) involution — undirected(1,2,5,3)(4,6,8,7)(10,15)(11,17)(16,22)(18,23)(9,11)(10,13)(12,18)(14,17)(15,21)(16,20)(19,23)(22,24)(25,28,31,34)(26,32,30,27)(29,36,38,40)(33,37,39,35)(1,3,5,2)(4,6,8,7)(9,12,14,19)(10,16,15,22)(11,18,17,23)(13,20,21,24)(25,29)(26,33)(27,35)(28,36)(30,39)(31,38)(32,37)(34,40)(1,4)(2,6)(3,7)(5,8)(9,13)(10,11)(12,20)(14,21)(15,17)(16,18)(19,24)(22,23)(25,30,31,26)(27,34,32,28)(29,33,38,39)(35,36,37,40)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.