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