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