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