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