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