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