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