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