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