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