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