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