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