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