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