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