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