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