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)(11,18)(12,16)(13,22)(14,17)(15,21)(19,24)(20,23)(25,26,31,35)(27,29,36,32)(28,33,38,40)(30,34,39,37)(1,3,5,4)(2,6,8,7)(9,11)(10,15)(12,19)(13,20)(14,21)(16,23)(17,18)(22,24)(25,27)(26,32)(28,33)(29,35)(30,34)(31,36)(37,39)(38,40)(1,3,5,4)(2,7,8,6)(9,12,14,13)(10,16,17,22)(11,19,21,20)(15,23,18,24)(25,28,31,38)(26,33,35,40)(27,30,36,39)(29,34,32,37)(9,13,14,12)(10,16,17,22)(11,20,21,19)(15,23,18,24)(25,29,31,32)(26,27,35,36)(28,37,38,34)(30,33,39,40)(1,4,5,3)(2,7,8,6)(11,21)(15,18)(19,20)(23,24)(25,30,31,39)(26,34,35,37)(27,28,36,38)(29,33,32,40)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.