One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,3,4)(5,6)(7,9)(8,10)(11,12)(13,14,16,17)(15,19,20,18)(5,6,8,10)(7,9,11,12)(13,14)(15,18)(16,17)(19,20)(22,25)(26,28)(7,11)(9,12)(14,17)(18,19)(21,22,24,25)(23,26,27,28)(1,2)(3,4)(5,6)(7,9)(8,10)(11,12)(13,15)(14,18)(16,20)(17,19)(21,23,24,27)(22,26,25,28)(5,7)(6,9)(8,11)(10,12)(13,14)(15,18)(16,17)(19,20) 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.