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