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