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