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