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