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