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