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