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