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