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