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